Claw shaped gouging cutter for fixed cutter drill bit

ABSTRACT

A cutter for use with a drill bit includes: a substrate for mounting in a pocket of the drill bit and made from a cermet material; and a head made from a superhard material, mounted to the substrate, and having a chisel or frusto-cone inclined relative to a longitudinal axis of the cutter by an attack angle ranging between fifteen and sixty degrees.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present disclosure generally relates to a claw shaped gouging cutter for a fixed cutter drill bit.

Description of the Related Art

U.S. Pat. No. 8,794,356 discloses an earth-boring tool including a body, one or more blades projecting outwardly from the body, and cutting elements carried by the blade. The cutting elements include at least one shearing cutting element and at least one gouging cutting element. Methods of forming an earth-boring tool include mounting a shearing cutting element including an at least substantially planar cutting face to a body of an earth-boring tool, and mounting a gouging cutting element including a non-planar cutting face to the body of the earth-boring tool. The gouging cutting element may be positioned on the body of the earth-boring tool such that the gouging cutting element will gouge formation material within a kerf cut in the formation material by the shearing cutting element, or between kerfs cut in the formation material by a plurality of shearing cutting elements.

U.S. Pat. No. 8,960,337 discloses a high impact resistant tool including a sintered polycrystalline diamond body bonded to a cemented metal carbide substrate at an interface, the body comprising a substantially pointed geometry with an apex, the apex comprising a curved surface that joins a leading side and a trailing side of the body at a first and second transitions respectively, an apex width between the first and second transitions is less than a third of a width of the substrate, and the body also includes a body thickness from the apex to the interface greater than a third of the width of the substrate.

SUMMARY OF THE DISCLOSURE

The present disclosure generally relates a claw shaped gouging cutter for fixed cutter drill bit. In one embodiment, a cutter for use with a drill bit includes: a substrate for mounting in a pocket of the drill bit and made from a cermet material; and a head made from a superhard material, mounted to the substrate, and having a chisel or frusto-cone inclined relative to a longitudinal axis of the cutter by an attack angle ranging between fifteen and sixty degrees.

In another embodiment, a cutter for use with a drill bit includes: a substrate for mounting in a pocket of the drill bit and made from a cermet material; and a head made from the cermet material, mounted to the substrate, and having a chisel or frusto-cone inclined relative to a longitudinal axis of the cutter by an attack angle ranging between fifteen and sixty degrees.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

FIGS. 1A-1D illustrate a claw shaped gouging cutter, according to one embodiment of the present disclosure.

FIGS. 2 and 3 illustrate a fixed cutter drill bit equipped with a plurality of the claw shaped gouging cutters.

FIGS. 4A-4D illustrate a second claw shaped gouging cutter, according to another embodiment of the present disclosure.

FIGS. 5A-5D illustrate a third claw shaped gouging cutter, according to another embodiment of the present disclosure.

FIGS. 6A-6D illustrate a fourth claw shaped gouging cutter, according to another embodiment of the present disclosure.

DETAILED DESCRIPTION

FIGS. 1A-1D illustrate a claw shaped gouging cutter 1, according to one embodiment of the present disclosure. The gouging cutter 1 may include a substrate 2 and a head 3 mounted to the substrate. The head 3 may be made from a polycrystalline superhard material, such as polycrystalline diamond (PCD), and the substrate 2 may be made from a hard material, such as a cermet. The cermet may be a cemented carbide, such as a group VIIIB metal-tungsten carbide. The group VIIIB metal may be cobalt. The gouging cutter 1 may be manufactured by a high pressure, high temperature (HPHT) sintering operation using either a belt press or a cubic press.

Alternatively, the head 3 may be made from a composite material, such as a cermet impregnated with superhard material, such as monocrystalline or thermally stable polycrystalline diamond. The cermet may be a cemented carbide and the diamond may be dispersed therein at a content ranging between twenty-five percent and sixty percent by volume. The gouging cutter 1 may then be manufactured by a hot isostatic pressing operation. Alternatively, the head 3 may be made from the same cermet material as the substrate 2.

The head 3 may have an interface 4 with the substrate 2, a chisel 5 at an end thereof opposite to the interface, a pedestal 3 p extending from the interface and connecting a side 5 s of the chisel to the interface, and a dome segment 3 d connecting a base 5 b of the chisel to the pedestal. The substrate 2 may have the interface 4 with the head 3 and a mounting end opposite to the interface for being received in a pocket of a drill bit 7. The mounting end of the substrate 2 may have a chamfer 2 c formed in a periphery thereof. The interface 4 may be planar or non-planar.

The pedestal 3 p may have a frusto-conical portion extending from the interface 4 and an irregular portion extending from the frusto-conical portion to the dome segment 3 d and to a side 5 s of the chisel 5. The chisel 5 may resemble a frusto-cone with the side 5 s having a truncated portion adjacent to the pedestal 3 p, the base 5 b having a truncated portion adjacent to the dome segment 3 d, and an edge 5 e formed by a pair of flats 5 f formed into opposite non-truncated portions of the side. The edge 5 e may be planar. The planar edge 13 e may have a slight curvature. The edge 5 e may have a length 6 e ranging between one percent and thirty percent of a diameter of the substrate 2, ranging between five percent and thirty percent thereof, or ranging between ten percent and thirty percent thereof. The edge 5 e may have a width 6 w ranging between one percent and sixty percent of the length 6 e thereof or ranging between ten percent and sixty percent thereof.

The chisel 5 may have an axis 6 c perpendicular to the edge 5 e and the base 5 b and inclined relative to a longitudinal axis 6 g of the gouging cutter 1 by an attack angle 6 a ranging between fifteen and sixty degrees. The flats 5 f may be formed in the chisel 5, such as by laser cutting or electrical discharge machining, after the gouging cutter 1 has been sintered. The head 3 may have a height 6 h greater than or equal to a thickness 6 t of the substrate 2 and less than or equal to the diameter of the substrate. The gouging cutter 1 may be symmetrical about a longitudinal plane extending through the edge 5 e.

Alternatively, the flats 5 f may be roughly formed during sintering and finished by laser cutting or electrical discharge machining.

FIGS. 2 and 3 illustrate a fixed cutter drill bit 7 equipped with a plurality of the claw shaped gouging cutters 1, 1 a, 1 b. The drill bit 7 may include a cutting face 9, a bit body 8, a shank (not shown), and a gage section 10. A lower portion of the bit body 8 may be made from a composite material, such as a ceramic and/or cermet matrix powder infiltrated by a metallic binder, and an upper portion of the bit body may be made from a softer material than the composite material of the upper portion, such as a metal or alloy shoulder powder infiltrated by the metallic binder. The bit body 8 may be mounted to the shank during molding thereof. The shank may be tubular and made from a metal or alloy, such as steel, and have a coupling, such as a threaded pin, formed at an upper end thereof for connection of the drill bit 7 to a drill collar (not shown). The shank may have a flow bore formed therethrough and the flow bore may extend into the bit body 8 to a plenum (not shown) thereof. The cutting face 9 may form a lower end of the drill bit 7 and the gage section 10 may form at an outer portion thereof.

Alternatively, the bit body 8 may be metallic, such as being made from steel, and may be hardfaced. The metallic bit body may be connected to a modified shank by threaded couplings and then secured by a weld or the metallic bit body may be monoblock having an integral body and shank.

The cutting face 9 may include one or more (three shown) primary blades 11 p, one or more (three shown) secondary blades 11 s, fluid courses formed between the blades, and the gouging cutters 1, 1 a, 1 b. The cutting face 9 may have one or more sections, such as an inner cone 12 c, an outer shoulder 12 s, and an intermediate nose 12 n between the cone and the shoulder sections. The blades 11 may be disposed around the cutting face 9 and each blade may be formed during molding of the bit body 8 and may protrude from a bottom of the bit body. The primary blades 11 p and the secondary blades 11 s may be arranged around the cutting face 9 in an alternating fashion. The primary blades 11 p may each extend from a center of the cutting face, across a portion of the cone section 12 c, across the nose 12 n and shoulder 12 s sections, and to the gage section 10. The secondary blades 11 s may each extend from a periphery of the cone section 12 c, across the nose 12 n and shoulder 12 s sections, and to the gage section 10. Each blade 11 may extend generally radially across the portion of the cone section 12 c (primary only) and nose section 12 n with a slight spiral curvature and across the shoulder section 12 s radially and longitudinally with a slight helical curvature. Each primary blade 11 p may be inclined in the cone section 12 c by a cone angle. The cone angle may range between five and forty-five degrees.

Each blade 11 may have a bearing face 11 f extending between a leading edge and a trailing edge thereof. Each blade 11 may be made from the same material as the lower portion of the bit body 8. The leading gouging cutters 1 a may be mounted, such as by brazing or interference fit, in respective leading pockets formed in the in the bearing faces 11 f of the primary blades 11 p adjacent to the leading edges thereof. The leading gouging cutters 1 a may be mounted into the leading pockets after infiltration of the bit body 8. The gouging cutters 1 may be mounted, such as by brazing or interference fit, in respective pockets formed in the in the bearing faces 11 f of the secondary blades 11 s midway between leading edges and trailing edges thereof. The gouging cutters 1 may be mounted into the pockets after infiltration of the bit body 8.

Starting in the nose section 12 n, each primary blade 11 p may have a row of backup pockets formed in the bearing face 11 f thereof adjacent to the trailing edge thereof and extending therealong through most of the shoulder section 12 s. Each backup pocket may be located to straddle a gap formed between adjacent leading pockets. The backup gouging cutters 1 b may be mounted into the backup pockets after infiltration of the bit body 8 and may be mounted by brazing or interference fit. The longitudinal axis 6 g of each gouging cutter 1, 1 a, 1 b may be transverse to a projection of the respective bearing face 11 f through the respective pocket, such as perpendicular or substantially perpendicular (plus or minus ten degrees forward rake angle). An effective forward rake angle of each gouging cutter 1, 1 a, 1 b may be determined by the sum of the forward rake angle and the attack angle 6 a thereof.

Each blade 11 may have an orientation guide (not shown), such as a hole, formed in the bearing face 11 f thereof adjacent to each pocket. During mounting, a technician or robot may align a back of the edge 5 e of each gouging cutter 1, 1 a, 1 b with the respective orientation guide, thereby ensuring the proper orientation of the gouging cutter. The proper orientation may be where a projection from the edge 5 e intersects the bearing face 11 f at a point closest to the respective leading edge. Positions of the gouging cutters 1, 1 a, 1 b may be staggered across the blades 11 to obtain complete and overlapping coverage.

One or more ports (not shown), such as a port for each blade 11, may be formed in the bit body 8 and each port may extend from the plenum and through the bottom of the bit body to discharge drilling fluid (not shown) along the fluid courses. A nozzle (not shown) may be disposed in each port and fastened to the bit body 8. Each nozzle may be fastened to the bit body 8 by having a threaded coupling formed in an outer surface thereof and each port may be a threaded socket for engagement with the respective threaded coupling. The ports may include an inner set of one or more ports disposed in the cone section 12 c and an outer set of one or more ports disposed in the nose section 12 n and/or shoulder section 12 s. Each inner port may be disposed between an inner end of a respective secondary blade 11 s and the center of the cutting face 9.

The gage section 10 may define a gage diameter of the drill bit 7. The gage section 10 may include a plurality of gage pads, such as one gage pad for each blade 11, and junk slots formed between the gage pads. The junk slots may be in fluid communication with the fluid courses formed between the blades 11. The gage pads may be disposed around the gage section 10 and each pad may be formed during molding of the bit body 8 and may protrude from the outer portion of the bit body. Each gage pad may be made from the same material as the bit body 8 and each gage pad may be formed integrally with a respective blade 11. Each gage pad may extend upward from an end of the respective blade 11 in the shoulder section 12 s to an exposed outer surface of the shank. Each gage pad may include a transition portion located adjacent to the shoulder section 12 s, a full diameter portion extending from the transition portion, and a tapered portion extending from the full diameter portion to the shank.

Alternatively, the gage pads may have gage protectors embedded therein. Each gage protector may be a thermally stable polycrystalline diamond.

In use (not shown), the drill bit 7 may be assembled with one or more drill collars, such as by threaded couplings, thereby forming a bottomhole assembly (BHA) (not shown). The BHA may be connected to a bottom of a pipe string, such as drill pipe or coiled tubing, thereby forming a drill string. The BHA may further include a steering tool, such as a bent sub or rotary steering tool, for drilling a deviated portion of the wellbore. The pipe string may be used to deploy the BHA into the wellbore. The drill bit 7 may be rotated, such as by rotation of the drill string from a rig (not shown) and/or by a drilling motor (not shown) of the BHA, while drilling fluid, such as mud, may be pumped down the drill string. A portion of the weight of the drill string may be set on the drill bit 7. The drilling fluid may be discharged by the nozzles and carry cuttings up an annulus formed between the drill string and the wellbore and/or between the drill string and a casing string and/or liner string.

As the drill bit 7 engages a rock formation (not shown) adjacent to the wellbore, each gouging cutter 1, 1 a, 1 b may gouge and/or crush the formation. As compared to conventional shear cutters, the gouging cutters 1, 1 a, 1 b may be mounted in pockets transverse to the bearing face 11 f instead of parallel thereto, thereby allowing more cutters to be mounted onto a given blade 11. The transverse mounting of the gouging cutters 1, 1 a, 1 b are much easier to braze into the respective pockets than conventional shear cutters and result in a better bond therein. Further, the gouging cutters 1, 1 a, 1 b have a much greater height than the thickness of conventional shear cutters, thereby providing greater protection to the bearing faces 11 f once the cutters become worn.

Alternatively, the secondary blades 11 s may have backup cutters similar to the primary blades 11 p. Alternatively, the blades 11 may have shear cutters as the leading cutters instead of the gouging cutters 1, 1 a.

Alternatively, the substrate 2 may have a knob (not shown) mounted to a back face thereof for orienting the gouging cutters 1, 1 a, 1 b. The knob may be formed separately from the rest of the gouging cutter 1, 1 a, 1 b and then mounted to the substrate thereof, such as by brazing. The knob may be angularly offset from the edge 5 e, such as being located opposite therefrom (one-hundred eighty degrees therefrom). The knob may be hemi-spherical and have a diameter ranging between twenty-five and forty-five percent of a diameter of the back face. Instead of an orientation guide adjacent to each pocket, the drill bit 7 may have a dimple (not shown) formed in the pocket thereof for mating with the knob, thereby ensuring that the gouging cutter 1, 1 a, 1 b has been properly oriented. The knob may be made from the same material as the substrate or a different material than the substrate, such as a metal or alloy, such as steel.

Alternatively, the substrate 2 may have a keyway (not shown) formed therein for orienting the gouging cutters 1, 1 a, 1 b. The keyway may be located at an edge of the substrate 2 and may extend from the back face thereof along a portion of a side thereof. The keyway may be a slot inclined relative to a longitudinal axis 6 g by an angle ranging between ten and seventy degrees. Instead of an orientation guide adjacent to each pocket, the drill bit 7 may have a mating key (not shown) formed in the pocket and the slot may have a width corresponding to a diameter of the mating key. The keyway may be angularly offset from the edge 5 e, such as being located opposite therefrom.

FIGS. 4A-4D illustrate a second claw shaped gouging cutter 13, according to another embodiment of the present disclosure. The second claw shaped gouging cutter 13 may be similar to the gouging cutter 1 except for having a modified chisel 14 with a wedge-shaped edge 14 e instead of the planar edge 5 e. The rest of the modified chisel 14 may be similar to the chisel 5. The wedge-shaped edge 14 e may have a length (see 6 e in FIG. 1A) and width (see 6 w in FIG. 1B) within the ranges discussed above for the planar edge 5 e. The second claw shaped gouging cutter 13 may be used with the drill bit 7 instead of the gouging cutters 1, 1 a, 1 b.

FIGS. 5A-5D illustrate a third claw shaped gouging cutter 15, according to another embodiment of the present disclosure. The third gouging cutter 15 may include a substrate 16 and a head 17 mounted to the substrate. The head 17 may be made from any of the materials discussed above for the head 3 and the third gouging cutter 15 may be made from any of the processes discussed above for the gouging cutter 1.

The head 17 may have the interface 4 with the substrate 16, a chisel 18 at an end thereof opposite to the interface, a pedestal 17 p extending from the interface and connecting a side 18 s of the chisel to the interface, and a dome segment 17 d connecting a base 18 b of the chisel to the pedestal. The substrate 16 may have the interface 4 with the head 17 and a mounting end opposite to the interface for being received in a pocket of the drill bit 7 instead of the gouging cutters 1, 1 a, 1 b. The mounting end of the substrate 16 may have the chamfer 2 c formed in a periphery thereof.

The pedestal 17 p may have a frusto-conical portion extending from the interface 4 and an irregular portion extending from the frusto-conical portion to the dome segment 17 d and to a side 18 s of the chisel 18. The chisel 18 may resemble a frusto-cone with the side 18 s having a truncated portion adjacent to the pedestal 17 p, the base 17 b having a truncated portion adjacent to the dome segment 17 d, and an edge 18 e formed by a pair of flats 18 f formed into opposite non-truncated portions of the side. The edge 18 e may be sharp. The edge 18 e may have a length (see 6 e in FIG. 1A) within the ranges discussed above for the planar edge 5 e. The edge 18 e may have an infinitesimal width (see 6 w in FIG. 1B).

The chisel 18 may have an attack angle (see 6 a in FIG. 1A) within the range discussed above for the chisel 5. The flats 18 f may be formed using the same process, discussed above for the flats 5 f. The flats 18 f may be primarily formed in the chisel 18 but may also extend slightly into the pedestal 17 p. The head 17 may have a height 6 h less than or equal to a thickness (see 6 t between FIGS. 1A and 1B) of the substrate 16 and less than or equal to the diameter of the substrate. The third gouging cutter 15 may be symmetrical about a longitudinal plane extending through the edge 18 e.

The attack angle 6 a of the gouging cutter 1 may be thirty-five degrees as shown while the attack angle of the third gouging cutter 15 may be twenty-five degrees as shown. The dome 17 d and pedestal 17 p differ accordingly with respect to the dome 3 d and pedestal 3 p.

Alternatively, the third gouging cutter 15 may have either the planar edge 5 e or the wedge-shaped edge 14 e instead of the sharp edge 18 e. Alternatively, the gouging cutter 1 may have the sharp edge 18 e instead of the planar edge 5 e. The sharp edge 18 e may perform better during drilling of softer formations, the planar edge 5 e may perform better during drilling of harder formations, and the wedge-shaped edge 14 e may perform better during drilling of intermediate hardness formations. The planar edge 5 e may have better impact resistance than the wedge-shaped edge 14 e and the wedge-shaped edge may have better impact resistance than the sharp edge 18 e.

FIGS. 6A-6D illustrate a fourth claw shaped gouging cutter 19, according to another embodiment of the present disclosure. The fourth claw shaped gouging cutter 19 may be similar to the gouging cutter 1 except for having a frusto-cone 20 instead of a chisel 5. A tip 20 t of the frusto-cone 20 may have a diameter corresponding to the length 6 e of the edge 5 e. The fourth claw shaped gouging cutter 19 may be used with the drill bit 7 instead of the gouging cutters 1, 1 a, 1 b.

Alternatively, the drill bit 7 may have a first set of one of the gouging cutters 1, 13, 15, 19 in the cone section 12 c, a second set of a different one of the gouging cutters in the nose section 12 n, and a third set of another different one of the gouging cutters in the shoulder section 12 s.

The priority provisional application U.S. 62/732,048, filed on Sep. 17, 2018, is herein incorporated by reference in its entirety.

While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope of the invention is determined by the claims that follow. 

1. A cutter for use with a drill bit, comprising: a substrate for mounting in a pocket of the drill bit and made from a cermet material; and a head made from a superhard material, mounted to the substrate, and having a chisel or frusto-cone inclined relative to a longitudinal axis of the cutter by an attack angle ranging between fifteen and sixty degrees.
 2. The cutter of claim 1, wherein a height of the head is greater than or equal to a thickness of the substrate.
 3. The cutter of claim 1, wherein the chisel or frusto-cone is the chisel having an edge.
 4. The cutter of claim 2, wherein with a length of the edge ranges between one percent and thirty percent of a diameter of the substrate.
 5. The cutter of claim 2, wherein the edge is sharp.
 6. The cutter of claim 2, wherein the edge is planar.
 7. The cutter of claim 2, wherein the edge is wedge-shaped.
 8. The cutter of claim 1, wherein the chisel or frusto-cone is the frusto-cone having a tip.
 9. The cutter of claim 8, wherein a diameter of the tip ranges between five percent and thirty percent of a diameter of the substrate.
 10. The cutter of claim 1, wherein the head is made from a polycrystalline superhard material.
 11. A bit for drilling a wellbore, comprising: a shank having a coupling formed at an upper end thereof; a body mounted to a lower end of the shank; and a cutting face forming a lower end of the bit and comprising: a blade protruding from the body; and the cutter of claim 1, wherein: the substrate is mounted in the pocket formed in the blade, and the pocket is transverse to a bearing face of the blade.
 12. A cutter for use with a drill bit, comprising: a substrate for mounting in a pocket of the drill bit and made from a cermet material; and a head made from the cermet material, mounted to the substrate, and having a chisel or frusto-cone inclined relative to a longitudinal axis of the cutter by an attack angle ranging between fifteen and sixty degrees. 